/*

    Copyright (C) 2016 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    Uses retroactive modeling to make `SKNode` a `Layout`.

*/

import UIKit

import SpriteKit

extension SKNode: Layout {

    typealias Content = SKNode

    func layout(in rect: CGRect) {

        // `SKNode` has a flipped coordinate system, so invert our Y coordinates.

        let height = parent?.frame.size.height ?? 0

        position = CGPoint(x: rect.midX, y: height - rect.midY)

    }

    var contents: [Content] {

        return [self]

    }

}

extension SKSpriteNode {

    override func layout(in rect: CGRect) {

        super.layout(in: rect)

        /*

            `SKSpriteNode`s have a settable size, so we'll update the node's size

            in addition to it's `position` (which is done in `SKNode`'s `layout(in:)`

            method).

        */

        size = rect.size

    }

}